Modern winders, for winding yarn into yarn packages on bobbins mounted on chucks, generally include two or more rotatable chucks each supporting one or more bobbins. The chucks are usually arranged in pairs on opposite sides of the support or housing for a yarn traverse mechanism, with each pair being associated with a common drive roll positioned adjacent the traverse support or housing. While one chuck is being rotated for winding of yarn into packages on bobbins mounted thereon, empty bobbins are placed on the second chuck which is then in a standby condition. When full packages have been wound on the first chuck, the yarn is transferred to bobbins on the second chuck and the first chuck is brought to a stop, after which the full packages are removed therefrom.
The fed yarn can be transferred from a full package to an empty bobbin or bobbins on the second chuck manually by a winder operator or attendant, who has to thread the yarn properly for winding on the bobbins or tubes on the second chuck. The threading of the yarn is usually effected by feeding the end of the yarn into an aspirator or the like, and then using a "doffer" to engage the yarn and the traverse guides for proper winding in a criss-cross manner on the bobbins on the chucks. However, such manual re-threading or re-guiding of the yarn, when full packages have been wound, so that the yarn can begin to be wound on empty bobbins, requires a considerable amount of time and, more importantly, a substantial waste of yarn, particularly when yarns are being fed at very high speeds.
A much faster and very highly efficient transfer of yarn from a full package on one chuck of a pair to an empty bobbin on the other chuck of the pair can be effected by the mechanism and method shown, described, and claimed in the Inventor's co-pending U.S. Patent application, Ser. No. 809,676, filed June 24, 1977, and by the mechanism and method shown, described and claimed in the Inventor's U.S. Patent Application Ser. No. 690,967, filed May 28, 1976, now U.S. Pat. No. 4,081,149.
In both these methods and mechanisms, the previously inactive chuck is accelerated to a high angular velocity before the yarn is transferred from the full package to an empty bobbin on the now rotating but previously inactive chuck. In order to effect high speed rotation of the previously inactive chuck, the latter, or the bobbin or bobbins thereon, must be brought into driving engagement with the common drive roll. It is thus necessary to move the inactive chuck horizontally, from an inactive and retracted position, past the package being wound on the then active chuck and into engagement with the drive roll for rotation by the latter. The necessity of leaving sufficient clearance for the inactive chuck, with a bobbin or bobbins mounted thereon, to be moved horizontally past a yarn package being wound on an active chuck, has limited seriously the diameter of the package being wound on the active chuck.
This limitation as to the size of the package which can be wound is of great importance when it is considered that the sector of the textile industry which involves man-made fiber production is becoming more competitive year by year with foreign production and more competitive internally. As a result, there is a great necessity to improve production speeds with a minimum cost of capital equipment. To attain these ends, the man-made fiber processors are constantly expanding their capability of making yarn at higher spinning speeds and with more threads per spinning position. Because there are now more threads per spinning position, the bottleneck for this expansion is the requirement for a winder which has higher speed capability and winds more and larger packages.
In order to be able to use existing spinning processing machinery and plant facilities, such a winder is a key objective. Without such a winder, completely new process facilities and plant facilities have to be built at continually higher costs for machinery.
The present invention is directed to making it possible to wind yarn at higher speeds and to obtain more and acceptably larger packages per winder.